I had an Italian flatmate for a while, and I was really surprised about the types of plants he'd make his pesto from. Basil was his favorite, but parsley, celery leaves, and arugula ('rucola') were also used. I've made my own from chickweed and kale, with peanuts instead of expensive pine nuts, and it's great. It freezes well in small containers, so we can have some on hand for the various dishes we like to make with it.

It's a peasant dish, and I appreciated the new insight I got into the rural Italian 'make-do' approach to it.

Sounds like a realy good thing to do with out of control garlic maustard. No, I haven't tried it, but I don't see how it could possibly taste like basil pesto. Maybe if you are comparing it to pesto that is more than half spinach. To me, though. pesto only has basil as its green leafy base. Garlic mustard sauce would just be a different dish.

In fact, from purslane, I make a cooked green sauce with oil and garlic, chopping the leaves as finely as I can (no food processor her, so that is done with a knife). It is tastey but I wouldn't consider it pesto even if I added the nuts and cheese.

My friends' kids eat spinach without reserve ever since they were little. That stands out to me because so many other kids I've seen won't eat spinach when young. The difference is that the parents make spinach into a spiced sauce that is spooned over rice or used as a dip for naan bread.